* Add support for Alexey Tourbin's QSORT code

See https://github.com/svpv/qsort

* Add benchmark scripts and compilation mode

Compile with `make O_BENCHMARK=1`, and run benchmarks with e.g.:
  ./misc/test/benchmark.sh ./nnn '/' '/usr/bin' '/usr/lib' > benchdata
You can then plot basic violin graphs with:
  ./misc/test/plot-bench.py benchdata

* Update style, doc, haiku support, fix lint

* Haiku: Some small fixes to the recipe and resource file

Whoops...just some small fixes.

* Update nnn.rdef

Co-authored-by: Jana <engineerarun@gmail.com>

* Add icons

* Fix build break

* Fix icon position in detailed mode

* Various fixes

* Provision for icon specific colors

No icons with oldcolor. Small optimizatons

* Update Makefiles

Small refinement for other matching

- Add a native vector icon for Haiku (it hasn't been Haiku-ified yet however)
- Add a rdef file (specifies application metadata)
- Add clipboard support, notififcation support, and basic nuke support
- Fix support for fortunes on Haiku ("-s" option is not available on Haiku)
- Cleanup Haiku recipe

Note that this is not compatible with 4 contexts.

* Add -a option to generate a temporary NNN_FIFO

* Add documentation for -a option

* plugins/README.md: promote the use of -a

This obsoletes the global FIFO unlink trick, so I remove mentions of it.
@jarun update:

Polish -a

This shows the "n³" logo as  icon in application menus, when desktop file is
installed (using `install-desktop` make target).

"n³" on a black knight chess piece/black horse head.

Install with `make install-desktop`
It now appears in application menus, search, etc. in XDG compatible
desktop environments (like GNOME, KDE, ...).

This reverts commit dbcbaa583c.

Replaces the following environment variables:
- NNN_USE_EDITOR
- NNN_IDLE_TIMEOUT